Proteomic Analysis of Cytokine Treated ARPE–19 Cells

Abstract

Abstract: : Purpose: Retinal pigment epithelium (RPE) cells have important functions in maintaining homeostasis of the outer retina. In addition, the RPE cells are thought to play an important role in immune responses. To better understand the cellular physiology involved in the immune response in the RPE, proteomic analysis of cytokine treated ARPE–19 cells was performed. Methods: Cultured human retinal pigment epithelium (ARPE–19) cells were treated with a single dose of cytokines (interferon–γ: 50 ng/ml; lipopolysaccharide 10 µg/ml and tumor necrosis factor–α 3.25 ng/ml) and harvested 24 hours later. Non cytokine treated ARPE–19 cells were used as a control cells. Comparative proteomic analysis between cytokine treated and non treated cells were performed by the following two different methods: 1) 2D–PAGE based method and 2) a newly developed mass spectrometry–based proteolytic ¹⁸O labeling method. Results: We observed a number of proteins whose expression levels were significantly up–regulated by the cytokine treatment. These proteins include interferon–induced guanylate–binding protein, toll–interacting protein, neuronal calcium sensor 1, intercellular adhesion molecule–1 and superoxide dismutase. Conclusions: The analyses of the obtained results are in progress. The results are expected to provide useful information to understand the cellular physiology involved in the immune response of the RPE cells.

Keywords: proteomics • retinal pigment epithelium • cytokines/chemokines